Henry a



(Nomaden l H. A. SEYMOUR.

ELECTRIC ARG LA MP. y N0. 574,117. -5 Patented Deo. 29, 1896.

TN: Ncnms PETERS cu, Pwoomwo, wAsHmGYoN, u c

UNITED STATES PATENT OFFICE.

HENRY A. SEYMOUR, OF IVASHINGTON, DISTRICT OF COLUMBIA.

ELECTRIC-ARC LAlVl P.

SPECIFICATION forming part of Letters Patent No. 574,117, dated December29, 1896.

Application filed .Tune 30, 1896.

T0 tif/ZZ whom, it ntcty concern:

3e it known that I, HENRY A. SEYMOUR, of W'ashington ,in the District ofCol u mbia, have invented certain new and useful Improvements in Arc-Lamps; and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to malte and use the same.

My invention relates to an improvement in arc-lamps, and especially tothat type of lamps which are operated by alternating currents.

IIeretofore many attempts have been made to produce an arc-lamp foroperation with an alternating` current, and while a measure of successhas been attained with lamps constructed to burn a short arc no one hasas yet succeeded in providing an alternatingcurrent lamp capable ofestablishing and maintaining a long arc within an arc-inclosi ng globe.It is absolutely essen tial to the establishment of an arc between thetwo electrodes of an alternating-current lamp that their adjacent endsbe first heated to such a degree as will result in the formation of abridge of conducting carbonaceous vapor across the gap or space betweenthem when separated. Without some provision for heating the adjacentends of the electrodes when currentis passed through analternating-current arclamp they will chatter violently for aconsiderable length of time before it is even possible to establish andmaintain a short arc, and this is due to the fact that as arapidly-alternating current is sent through the cold electrodes thecurrent falls to zero so rapidly that the carbons cannot be maintainedseparated for a sufficient length of time to insure their being heatedto such a degree as will insurethe maintenance of an arc between them.Hence the slight arc formed between the cold carbons is rapidlyestablished and broken, resulting in a rapid and violent chattering ofthe carbons and regulating mechanism,which continues until the ends ofthe carbons have become sufficiently heated to insure the production ofa conducting bridge of carbon vapor across the gap or space betweenthem, and then, and not until then, is a persisting are established.

The operation of alternating-current arc- Serial No. 597,612. (Nomodel.)

lamps as heretofore constructed has been attended by a constant hissingof the arc and buzzing of the regulating mechanisim'whieh has proved soannoying and objectionable as to have very largely restricted their use.

Attempts have been made to overcome the difficulties above set forth b vso constructing the regulating mechanism that it would operate to veryslowly separate the feeding carbon from the non-feeding carbon and thusinsure the establishment of a persisting arc between them; but lamps soconstructed proved inefficient and defective in their operation fortworeasons. First, the application of means to the regulating mechanism forretarding the initial separating movement of the feeding carbon operatedto deprive the regulating mechanism of that delicate and sensitiveaction which is essential to the proper regulating and feed of thecarbon and to the maintenance of a persisting are, and, second, byimposing upon the regulating mechanism the duty of separating thecarbons and establishing and drawing a long are, it rendered itimpossible to maintain such a relation between the core and solenoid orarmature and helix of the regulating mechanism as would insure itsprompt and sensitive action in regulating and feeding the carbon.

The object of my invention is to provide an arc-lamp of suchconstruction that the function of slowly separating the carbons andgradually drawing the arc to any desired length shall be performed bymechanism associated with and acting upon the lower or non-feedingcarbon, while all the functions necessary to the regulation and feedingof the carbons shall be performed by mechanism associated with andacting upon the feeding carbon.

A further Objectis to provide means for preventing the rapid vibrationof the carbons or of the regulating mechanism when the lamp is inoperation. A further object is to provide an improved construction andarrangement of parts for supportingan arc-inclosing globe.

Vith these ends in View the invention consists in certain features ofconstruction and combinations of parts, as will be hereinafterdescribed, and pointed out in the claims.

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.ln the accompanying t'lrawings7 Figure il a view7 partly in verticalsection and partly in side elevation, of an arc-lamp embodying myinvention; and Figs, 2 and f3 are detailed views of the dash-pot.

A represents the lamp-floor, Y[from which is suspended thesupperting-bracket 13, which is insulated l'rom the lloor and isstrengthened and stitlened by means ot the short bracketarin e and ringb, said parts being either east in a single piece or made separate andl'astened together in any desired manner.

C is a solenoid supported in the lower end of bracket B. To the core Dol the solenoid is attached a carbei'i-holding socket c, which isinsulated trom the core at d. A spiral spring E serves to uphold thecore and the lower carbon li". Helix is composed of conductor ot"comparatively low resistance which is connected at one end to socket cby the flexible conductor g, while its opposite end is electricallyconnected atfwith bracket i3. To the under side of the solenoid issecured a dash-pet ll, which is illustrated in detail in Figs. 2 and il.Piston-rod g oi' the dash-petis connected to core D. Piston ll' isprovided with an adjustable screw-valve ll?, by means of which the speedof the piston throughout its downward stroke may be retarded to anydesired extent. in order to insure a prompt and quick upward movementoi' the core and lower carbon, piston ll is provided with any desirednumber of passages 7L', through which extend the stems 7L?, which aresecu red at their lower ends to an annular ring-valve H3, which seatsover and closes the passages 7l. Each one ot the stems hf is encircledby a spiral spring h3, which is seated at one end on the top ot' thepiston. and at its opposite end against a collar or head on the upperend of the stem. ly this construction ol dash-pot the movement of thelower carbon may be retarded and made very slow and gradual throughoutthe entire downward movement, while its upward movement will be quickand prompt.

l is a shunt-solenoid, its helix 'i being coinposed ot' line wire ofcomparatively high resistance and electrically connected at its eppositeends with opposite binding-posts J J' ot' the lamp. This solenoid issupported above the floor b v brackets l" or in any othei' desiredmanner.

I' is a hollow core having a diamagnetic tube l2, secured te its lowerend. A spider l:E is attached to the lower end el tube l2, and toitsouter rim are adjustably secured the lower ends ol spiral springs l",which are secured at. their upper ends to the lower head et' thesolenoid. The drawings illustrate only two springs7 while tour or moremay be employed and arranged at equal distances apart around the tubeil. A tubular carbon rod or holder K, passes down through the hollowcore and tube and through the floor ot the lamp, it being encircled byan annular ring valve K', which 'is seated. upon the lamp-floor andsnugly lits the carbon-rod. and serves to prevent the passage oi gasesinto the casing containing the regulating mechanism.

L a ring-clamp surrounc'liug` the carbonholder and resting upon thering-valve l\"'. This clamp is provided with a groove 7u, into whichprojects the linger 7i" ol' the lilter A stop lo liinil'sthe upwardmovement ol' the ring-clamp.

lllithin the hollow carbon rod or holder is a piston l, which issuspended by a red attaehed at its upper end to the top ot' the casing,whereby the carlmn-red and piston serve as a daslrpot to steady theaction ot' the npper carbon. To the carbon-rod is altzuhcd. by aball-and-socket joint ZVJ a cover ill, which is constructed with asocket p1, in which the feeding carbon F secured by a set-screw in.Aresinelosing globe N connected to cover .M by means el setscrews n,which hear against the beveled surface/n on the globe and thereby Ytorceits ends into snug engagement with the cover. instead of employing thel'aslcn ing devices shown any suitable means may be used lor securinglthe globe to the cover, so as to torni practically an air-tight jointbe4 tween them. The cover is provided with a satetywalve n@ to n'cventan excess ot' pres* sure within theglobe. The bottom ol the areinclosingglobe is provided with a cover()1 having an opening o formed therein,through which the lower carbon li" passes and. within which it snuglylits.

Outer globe l" is ln'ovided at its upper end with an outwardly-flaringllange jp, which seats against the inclined face ot a bearing p, `termeden the under side ot the lloor olI the lamp or connected thercwil h.l`he globe is secured in placebymeans ol the set. .s rows pi and isrendered tight by the metall stripp" litting snugly against the bearingVp. Het screws p2 by their engagement with the inv clined surface en the`l'lange p operate to l'oree the latter into snug Contact with the`inclined seat p. Casing (u) may be made el a single casting or may henri vided with suitable doers or covered openings and is secured to thelam p-lloor by screws q.

The operation ot the lamp is as lollows: Yllhen no current is passingthrough the lamp, its cai-bons are very slightly separated, the uppercarbon, together with the are-inclosing globe, being uphold by thesprings ll, which serve to lit't the hollow core and litter and causet-he ring-clamp to grip the carbon-rod and support it in its raisedposition. lllhen current is passed through the lamp, it first ilowsthrough the helix ol the shuntssolenoid and energizes the lattersul'liciently te cause it to pull down thc hollow cere and upper carbonand to bring the two carbons into con tact. immediately the carbons arebrought into contact practically the entire current will l'low from.binding-post J' through the lamp-licor A, carbon-holder l, carhonslsolenoid. C, bracket ,I3 te the binding-post- J', '.llie passage ol theand from thence to line.

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current through the lamp will operate to weaken the shunt-magnet andpermit the springs 71;4 to lift the upper carbon and thereby establishan arc between the two carbons; but this are will be very short, owingto the fact that the stop k3 will so limit the upward movement of theupper carbon that it will be separated but a very slight distance fromthe lower carbon. At the same time the passa-ge of the current throughthe carbons, when brought into contact,will energize solenoid C andcause it to pull down its core and lower carbon supported by it; but thedownward movement of the lower carbon is so retarded by the dash-pot IIas tocause it to separate very slowly and gradually from the uppercarbon, and hence it continues to descend until it has drawn an are ofany desired length. The very slight initial separation ofthe carbons,due to the upward movement of the feeding carbon, operates to insuresuch a resistance to the passage of the current as will result in therapid heating of the ends of the carbons without interrupting thecircuit and extinguishing the arc, and the slow and gradual descent ofthe lower carbon will insure the drawing of an are of any desired lengthwithout extinguishing it.

Instead of operating in the manner above described the parts may be soadjusted that the carbons will be in contact when no currentis passinthrough the lamp. Now on the passage of current through the lamp thelower carbon will be drawn down very slowly,with the result that anexceedingly minute arc will be iirst established between them, which arcwill sufiice to heat their adjacent ends and insure the maintenance ofthe arc,which will gradually be elongated until it has been slowly drawnto any desired length. An arc of normal length having been thusestablished between the two car-bons, it will continue to burn, and asit grows longer its resistance will increase,with the result that anincreased amount of current will flow through the shuntsolenoid, and sostrengthen it until it will pull down its core and cause the uppercarbon to feed through the ring-clamp, and thus maintain a normal lengthof are.

Owingto the fact that the pull of the shuntmagnet varies with and is atall times dependent upon the resistance of the are, the regulatingmechanism is so constructed and adj Listed that not until an arc ofnormal or predetermined length has been established by the downwardmovement of the lower carbon will such an equilibrium of forces beestablished between the shunt-magnet and the opposing springs as willinsure that delicate and sensitive automatic adjustment and feed of theupper carbon which is necessary to the maintenance of a persisting arcof uniform length and brilliancy.

In order to prevent the rapid vibration of the upper carbon and thefluctuation of the arc and light produced by it, a dash-pot formed of apiston working in the hollow carbon-rod is employed to slightly retardand check the upward-and-downward movement of the feeding carbon, andstill permit of a sufficiently prompt and sensitive action of theregulating mechanism to insure a steady and uniform light.

As an additional means for steadying the arc and for preventing anyvibrations of the feeding carbon and regulating mechanism, theshunt-magnet is provided with a closed diamagnetic conductor I, whichpreferably consists of a closed tube of copper which may be locatedeither inside oroutside of the linewire helix. On the passage of analternating current througha solenoid the rapid rise and fall of thecurrent will induce eXtra currents in the coils of the helix, which,acting on the core, will cause it to vibrate and impart very slight andrapid iiuctuations tothe arc. To obviate this trouble, a closeddiamagnetic conductor I is placed either inside or outside of the helixand serves to suppress such eXtra current and thus shield and protectthe core against theinlfluences of such rapid magnetic impulses, andenable a steady and reliable arc to be maintained.

In the event the arc should be extinguished from any cause the lowersolenoid will be dc-nergized, with the result that the lower carbon willbe instantly raised by the spiral spring D and brought into contact withthe upper carbon, the dash-pot being constructed to permit of the quickupward movement of its piston, thus instantly re-stablishing the arcbetween them.

By mounting the are-inclosin g globe in the manner shown the escape ofgases from the globe and the ingress of outerairthereto may be preventedby means of a cover which will permit of greater freedom of action tothe carbon passing through it than is possible when the carbon is fedthrough the top of the globe for the following reason.

It has been practically demonstrated that the speeic gravity of thegases generated within an arc-inclosing globe is slightly less than thatof the outer air, and hence the tendency of such gases is to rise andescape through the opening formed between the carbon and the walls ofthe hole in the cover through which the carbon is fed. Hence in lamps asheretofore constructed it has been found-necessary to form a tightjointaround the upper and feeding carbon to prevent the escape of gases andingress of outer air,and the means resorted to forproducing such tightjoint have been found to more or less interfere with the adjustment andfeed of the carbon. By inverting the globe and providing its upper endwith a tight imperforate cover, which will prevent the rise and escapeof gases from the globe and also the fall of the outer air into itsupper end, the gases generated therein will be confined within the globeand form a seal around the are, which will be preserved by a coverapplied to the lower end of the globe and having a hole TOO IOS

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l'orined therein ol' such size that the lower carbon may freely slidetherein.

By connecting both the upper carbon and the arc-inelosing globe to thecarbon rod or holder by a ball-and-socket joint and causing` the lowercarbon to serve as a guide for the lower end of the globe and uppercarbon the two carbons are retained in alinement and ample lateralmovement in all directions is afforded the globe to provide for anyirregularities that may exist on the surface of the lower carbon.

To trim the lamp, the set-screws p2 are loosened and the outer globe Pis lowered and suspended from bracket B by means of the sliding`connection S, connected at one end with the metal strip 2f; and engagingthe bracket at its forward. end.

IVhile the lamp iis especiallyv adapted for use with an alternating`current on constantpotential circuits, it is evident that it may be usedwith a straight current and also maybe used on'constant-eurrentcircuits.

IIaring fully described my invention, what I claim as new, and desire tosecure by Letters Iatent, is-

ll. In an are-lamp, the combination with its earbons and means `forretaining them slightly separated when no cu rreut is passingv throughthe lamp, of means .for automatically bringing` the earbons into Contactand means for separating; them very slightly when current is sentthrough the lamp and means for slowly and graduallyseparating'thenon-fecding car bon from the feeding; carbon and therebyslowly drawing; the arc to any desired length, substantially as setforth.

2. In an arc-lamp, the combination with the lower and non'leedingcarbon, oi' means for slowly and gradually separating' it from the upperand 'feeding carbon and thereby drawinf;` an arc ot' any desired length,of means for permitting of the quick upward movement of the lowercarbonwhen the are is extinguished, substantially as set forth.

El. In an arelamp, the combination with its cai-bons, of anarcinelosinib l globe constructed and arranged to be Ied downward withthe` upper carbon, and provided with a cover at its lower end withinwhich the lower carbon snugly lits, substantially as set t'orth.

l. In an are-lamp the combination with the carbon-holder and the upperand. lower earbons, of an arc-inelosing globe connected with andsuspended from the carbon-holder, said globe being provided at its lowerend with a cover in which the lower carbon snugly fits, substantially asset forth.

5. In an are-lampthe combination with the carbon-holder, and lower andnon-feeding carbon, oi' an arc-inclosingl globe and feeding carbon,suspended from the carbondlolder by a universal joint, said globe beingprovided with a cover on its lowerend having au open ing in it throughwhich the lower carbon passes, substantially as set i'orth.

(i. In an arcslamp the continuation wilh the carbon-holder, lamp-floorand annular valve encircling the carbon-holder and seati ng upon thelamp-'iloor, oi' a ring-clamp located over and adapted to rest upon saidannular vulve, substi'intially as set `forth.

7. In an arcdamp the combination with its cai-bons of an are-inelosinglglobe suspended from `its upper end, whereby its lower end is adapted tomove laterally in any f lreetion, the lower end o'l the globebeinflprovided with a cover having' an opening through whit-h the lower carbonpasses, substantially as set lorth.

In testimony whereof I have signed this specification in the presenceol. two subst-rib ing` witnesses.

.HENRY A. SIC'YIUlIh.

Witnesses G. Nor'jrxeiftiin, G. F. DowNrNo.

